Spectrometer mount and measuring apparatus including same

ABSTRACT

A spectrometer  1 A is constituted with an optical body  10,  a glass member  11  formed with a light entry slit  12,  and a connecting flange  20.  The connecting flange  20  is provided with an opening  21  to which the glass member  11  is positioned and inserted, and with positioning rods  25  provided in positions in front of and behind the opening  21  as positioned relative to the opening  21.  Using the positioning rods  25,  when the spectrometer  1 A is applied to the measuring apparatus, makes it possible to connect the spectrometer  1 A and other components of the measuring apparatus through a passive alignment method simply with high accuracy. Thus, a spectrometer capable of favorably achieving optical connection to light to be optically separated and a measuring apparatus using the spectrometer can be realized.

TECHNICAL FIELD

This invention relates to a spectrometer for separating incident lightand a measuring apparatus using the spectrometer.

BACKGROUND ART

A spectrometer is an optical device for separating light to be measuredinto its spectral components with a dispersive element such as a prismor a diffraction grating. By detecting the spectral component of lightseparated by the dispersive element, the wavelength distribution of thelight or the intensity of a specific wavelength component of the lightcan be known. Thus, spectrometers are used in a variety of applicationareas (for example, See Patent Document 1: Japanese Patent ApplicationLaid-Open No. 2000-65642).

DISCLOSURE OF THE INVENTION

Small-sized spectrometers are generally applied to various spectroscopicmeasuring apparatuses and measuring systems. Such measuring apparatusesare constituted for example with: a light source for providing light, alight guide optical system, a spectrometer, and a measuring circuit.

When a spectrometer is applied to measuring apparatuses, optical fibersare often used for optical connection for letting object light to beoptically separated into the spectrometer because the optical fibers canbe installed easily with high accuracy. The types of optical fibers tobe used include a single optical fiber having a large core and a fiberbundle. Here, the optical fiber having a large core is relatively rigid.A bending radius of a typical large-core optical fiber of a corediameter of 600 μm and a clad diameter of 720 μm is about 20 cm, forexample.

On the other hand, when a fiber bundle is used for optical connection toa spectrometer, the fiber bundle must be protected against bending toachieve favorable optical connection and to prevent bending loss leadingto poor measuring accuracy. Therefore, it is a common practice toprotect the fiber bundle with a rather rigid tube or the like. Asdescribed above, since a certain extent of space is required to lay theoptical fiber when a constitution is employed in which the fiber bundleor optical fiber having a large core is used for the optical connectionto the spectrometer, a problem arises that the measuring apparatus as awhole becomes large in size.

In contrast to the above, it is considered to constitute a measuringapparatus without using an optical fiber for the optical connection tothe spectrometer. In that case, the object light to be opticallyseparated is cast through a light entry section of a slit shape or thelike into the spectrometer. In such a constitution, however, since thespectrometer must be placed with high accuracy using an active alignmentmethod relative to other components in the measuring apparatus, aproblem arises that much time is required for positioning the apparatus.There are also problems about long term stability of the apparatusconstitution, manufacturing cost, or the like.

This invention has been made to solve the above problems and therefore,an object of this invention is to provide a spectrometer capable ofachieving favorable optical connection for the object light and ameasuring apparatus using the spectrometer.

To accomplish the above object, a spectrometer of this inventioncomprises: (1) a spectroscopic section used for separating incidentobject light into its spectral components, (2) a light entry sectionprovided in a predetermined position relative to the spectroscopicsection for permitting entry of the object light into the interior ofthe spectroscopic section, (3) a connecting member used to connect thelight entry section and the spectroscopic section to a predeterminedother member, and (4) a positioning element provided as positionedrelative to the light entry section for positioning the light entrysection relative to the other member.

The above spectrometer is constituted that the connecting member and thepositioning element used for connecting the spectrometer to anothermember are provided in a predetermined positional relationship to thelight entry section which permits the light, the object of opticalanalysis, enter the interior of the spectroscopic section underpredetermined incident conditions. This makes it possible, when thespectrometer is applied to the measuring apparatus, to interconnect thespectrometer and other component elements of the measuring apparatuswith high accuracy to favorably achieve the optical connection of theobject light to be optically separated to the spectrometer. The aboveconstitution, in particular when applied to the measuring apparatus,makes it possible to carry out positioning by passive alignment methodand makes it easy to assemble the measuring apparatus including thespectrometer.

Here, the spectroscopic section may employ any specific constitution.For example, a constitution may be employed using a dispersive element,a photodetector, and the like. Another constitution may use an opticalbody made of a material that permits passage of a specific wavelengthrange of light. As for the positioning element provided in predeterminedpositional relationship to the light entry section, it is preferable toprovide in a plural number, two or more, so as to enable two-dimensionalpositioning, etc. Or, it may be used in combination with anotherpositioning section.

As for the specific constitution of the light entry section, it ispreferable to provide a light entry member in which a light entry slitserving as the light entry section is formed on a predetermined surface.In this way, it is possible to favorably achieve the placement of thelight entry section relative to the spectroscopic section, connectionand positioning when applying the spectrometer to the measuringapparatus. Such a light entry member can be made of a material thatpermits passage of a specific wavelength range of light.

The connecting member preferably has a first positioning section usedfor positioning relative to the light entry section and a secondpositioning section serving as the positioning element. The positioningelement can have the form of a protrusion, recess, edge, angle and thelike. Using the connecting member constituted as described above, it ispossible to carry out reliably connection and positioning of thespectrometer to other members in the measuring apparatus. As for thespecific form of the connecting member, a connecting flange using aplate-like member is preferable.

The spectrometer preferably includes a light entry member in which alight entry slit serving as the light entry section is formed on apredetermined surface, wherein the connecting member has a firstpositioning section used for positioning relative to the light entrymember and a second positioning section serving as the positioningelement, and wherein the first positioning section includes an openinginto which the light entry member is positioned and inserted.

The spectrometer may also be constituted by using the positioningelement, made of a positioning member positioned relative to the lightentry section. It may be otherwise constituted by using the positioningelement, positioned and mounted to the light entry member.

The measuring apparatus of this invention comprises: (1) thespectrometer as described above, (2) an optical system for guiding theobject light to the light entry section of the spectrometer, and (3) aholding member connected to the connecting member of the spectrometerfor holding the spectrometer and the optical system as positioned.

The arrangement described above, using the spectrometer having theconnecting member and the positioning element, makes it possible toprovide a measuring apparatus capable of accurately positioning thespectrometer relative to other component elements of the apparatusthrough a passive alignment method. Using the positioning element forpositioning the spectrometer facilitates the manufacture of themeasuring apparatus.

With the spectrometer and the measuring apparatus according to thisinvention, the constitution in which the connecting member and thepositioning element for connecting the spectrometer to another memberare provided in a predetermined positional relationship to the lightentry section which permits the object light enter the interior of thespectroscopic section, makes it possible to interconnect and positionthe spectrometer and other component elements of the measuring apparatuswith simplicity and high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view showing the constitution of aspectrometer as the first embodiment.

FIG. 2 shows the constitution of the spectrometer in a side view (a), aside view (b), and a plan view (c), as seen from the positive side ofthe x-axis, y-axis, and z-axis, respectively.

FIG. 3 is a perspective view roughly showing the constitution of ameasuring apparatus as an embodiment.

FIG. 4 is an exploded perspective view showing the constitution of aspectrometer as the second embodiment.

FIG. 5 is an exploded perspective view showing the constitution of aspectrometer as the third embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

Details of the spectrometer according to this invention and themeasuring apparatus using the spectrometer are described in reference topreferable embodiments and the appended drawings. In the description ofthe drawings, the same elements are denoted with the same referencesymbols and redundant description is omitted. It is also noted that thedimensional ratios in the drawings do not always the same as those inthe description.

First, a constitution of the spectrometer according to this invention isdescribed.

FIG. 1 is an exploded perspective view showing the constitution of thespectrometer according to a first embodiment of this invention. Here,for the convenience of description, x-axis, y-axis, and z-axis extendingat right angles to each other are defined as shown in FIG. 1. Besides,when required for description, the negative and positive directions ofthe x-axis are assumed to be left and right directions, respectively,those of the y-axis to be forward and backward directions, and those ofthe z-axis to be downward and upward directions.

FIG. 2 shows the constitution of the spectrometer shown in FIG. 1, inwhich (a) is a side view as seen from the positive side of the x-axis,(b) is a side view as seen from the positive side of the y-axis, and (c)is a plan view as seen from the positive side of the z-axis.

A spectrometer 1A of this embodiment is provided with: an optical body10, a glass member 11, and a connecting flange 20, in a constitutioncapable of achieving simple, accurate alignment of the spectrometer 1Awhen the spectrometer is applied to a measuring apparatus, as describedlater. The incident direction of light for this spectrometer 1A is inthe negative direction of the z-axis in FIG. 1.

The optical body 10 is made of a transparent material such as glass or atransparent resin material that permits passage of the object light foroptical analysis by means of the spectrometer 1A, in a cylindrical shapecentered on the z-axis. In this embodiment, a spectroscopic section usedfor separating the incident object light into its spectral components isconstituted with: the optical body 10, a light entry slit 12 and aphotodetector 17 both provided on the top surface 10 a of the opticalbody 10, and a diffraction grating 16 provided on the underside 10 b ofthe optical body 10.

FIG. 1 shows a diffraction grating 16 of a concave surface reflectiontype serving as the dispersive element for separating the object lightinto its spectral components and formed on the underside 10 b, with thex-axis direction assumed to be the light dispersion direction. Such adiffraction grating 16 can be made for example by forming on theunderside 10 b a diffraction grating pattern such as a blazed grating atthe time of forming the optical body 10, followed by applying areflective coating such as of aluminum onto the area where the patternis formed.

What is used as the photodetector 17 is for example a photodiode array(photodetection element array) made up of plural photodiodes(photodetection elements) arranged in a row in the direction of thex-axis which is the same as the direction of light dispersion with thediffraction grating 16. With the above constitution, the light coming inthrough the light entry slit 12 into the optical body 10 is reflectedand also separated with the diffraction grating 16 as the dispersiveelement. Resultant spectral components are detected with the photodiodearray 17 to carry out spectrometric measurements of the object light.The spectroscopic section may be in any constitution, without beinglimited to the specific example shown in FIG. 1.

In addition to the photodiode array 17, a glass member (glass spacer) 11is placed on the top surface 10 a of the optical body 10. The glassmember 11 is a light entry member whose predetermined surface is formedwith the light entry slit 12 serving as a light entry section thatpermits the entry of an object light under predetermined incidentconditions (incident range, incident angle, etc. of light) into thespectroscopic section including the optical body 10. Specifically, theglass member 11 can be made of a material that permits passage of lightof a predetermined wavelength range, preferably in the shape of a mainlyrectangular parallelepiped of a predetermined thickness. The undersideof the glass member 11 in contact with the optical body 10 is formed byphotolithography with a light entry window pattern 13 including therectangular light entry slit 12.

The light entry slit 12 provided on the glass member 11 is to determinethe path of the object light incident into the optical body 10. Theglass member 11 and the photodiode array 17 are placed in position onthe top surface 10 a with required positional accuracy relative to theoptical body 10 provided with the diffraction grating 16. Thepositioning of the glass member 11 and the photodiode array 17 iscarried out in either passive alignment method or active alignmentmethod depending on dispersion accuracy and performance specificallyrequired of the spectrometer 1A and on tolerances allowed.

A connecting flange 20 of a plate-like shape is attached to the topsurface 10 a of the optical body 10 relative to the optical body 10 andthe glass member 11. The connecting flange 20 is a connecting memberused for connecting the light entry section made of the light entry slit12 and the spectroscopic section including the optical body 10 to apredetermined other member. The other member (the member additional tothe spectrometer) for connecting the spectrometer 1A is for example, aswill be described later, other component member of the measuringapparatus to which the spectrometer 1A is intended for application.

The connecting flange 20 is provided with an opening 21. The opening 21is provided in a position corresponding to the glass member 11 in thesame rectangular shape as the glass member 11 as seen in the z-axisdirection. Two side surfaces 11 a and 11 b of the glass member 11 andcorresponding two side surfaces 21 a and 21 b of the opening 21 serve aspositioning surfaces (reference surfaces) for mutual positioning of theglass member 11 and the connecting flange 20 with high accuracy as thesurfaces come into contact with each other. In this way, the glassmember 11 serving as the light entry member is inserted into the opening21 and positioned relative to the connecting flange 20. The opening 21serves as the positioning section (first positioning section) used forpositioning relative to the light entry section. The light entry slit 12is formed in the glass member 11, as positioned relative to thepositioning surfaces 11 a and 11 b.

The top surface of the connecting flange 20 is provided with twopositioning rods 25, one in front of and the other behind the opening21. These positioning rods 25 are of a cylindrical shape projectingupward from the connecting flange 20 and placed with high accuracy inposition relative to the positioning surfaces 21 a and 21 b, serving asthe first positioning sections, of the opening 21. Here, the positioningrods 25 are positioned through the opening 21 relative to the glassmember 11 including the light entry slit 12. In this manner, when thelight entry section made of the light entry slit 12 and thespectroscopic section including the optical body 10 are connected to theother member, the positioning rods 25 serve as the positioning elements(second positioning sections, positioning protrusions) used forpositioning the light entry section relative to the other member.

As shown in FIG. 2 with views (a) to (c), the optical body 10 and theglass member 11 is placed in a container 15 surrounding those. A housingof the spectrometer 1A for housing the optical body 10 and the glassmember 11 is made up of the container 15 and the connecting flange 20.The connecting flange 20 is provided with securing holes 22 in specifiedpositions, one each on left and right, for use when the other member isconnected by means of screws. Illustration of the constitution insidethe housing except for the glass member 11 is omitted in FIG. 2.

Effects of the spectrometer of the above embodiment are described below.

In the spectrometer 1A shown in FIGS. 1 and 2, the light entry slit 12provided on the glass member 11 serving as the light entry section isused for letting light to be optically separated into the spectroscopicsection made up of the optical body 10, the diffraction grating 16, andthe photodiode array 17. Here, a constitution is employed in which theconnecting flange 20 serving as the connecting member of a plate-likeshape used when the spectrometer 1A is connected to the other member andthe positioning rods 25 serving as the positioning elements are providedin a predetermined positional relationship to the light entry slit 12.With the above constitution, the spectrometer 1A and the other member ofthe measuring apparatus are interconnected with high accuracy when thespectrometer 1A is applied to the measuring apparatus, so that opticalconnection of the object light to the spectrometer 1A is achieved in apreferable manner.

In particular as described above, it is possible to use a passivealignment method to position the spectrometer 1A when the spectrometer1A is applied to the measuring apparatus by using the positioning rods25 for positioning the light entry slit 12 provided on the glass member11 and the other component element present on the measuring apparatusside. Therefore, it is possible to achieve the connection of thespectrometer to the other member and assembly of the measuring apparatusincluding the spectrometer at a low cost, within a short period of time,and in a simple manner. Such a constitution is excellent also in termsof long-term stability of the device constitution. Here, the positioningelement can have the form of a protrusion, recess, edge, angle and thelike.

In the constitution shown in FIG. 1, as for the light entry section forpermitting the entry of object light into the spectroscopic section, theglass member 11 serving as the light entry member formed with the lightentry slit 12 is used. In this way, it is possible to carry out in afavorable manner placement of the light entry section relative to thespectroscopic section and connection and positioning when thespectrometer 1A is applied to the measuring apparatus. In the aboveconstitution, the positioning surfaces 11 a and 11 b are vertical to thetop surface of the glass member 11 and the positioning surfaces 21 a and21 b of the opening 21 are vertical to the underside of the connectingflange 20. The above constitution makes it possible to carry outpositioning in the rotation around the z-axis as well as in the x-axisand y-axis directions.

As to the glass member 11, the connecting flange 20 is provided with theopening 21 serving as the first positioning section for positioningrelative to the glass member 11 and the light entry slit 12, and withthe positioning rods 25 serving as the second positioning sections, orthe positioning elements, for positioning relative to another member.Using the connecting flange 20 as the connecting member makes itpossible to carry out reliably the connection and positioning of thespectrometer 1A relative to the measuring apparatus.

Such a connecting flange 20 may be produced by precision machining ofthe opening 21 and the like using laser cutting technique. Thepositioning rods 25 may be arranged that the connecting flange 20 isprovided with holes positioned relative to the opening 21 and precisionrods are secured into the holes, so that they serve as the positioningrods 25. The whole connecting flange 20 may be formed as a single bodyby precision injection forming.

As for the positioning elements provided in predetermined positionalrelationship with the light entry section in the spectrometer, it ispreferable to provide two or more of them to enable positioning withhigher accuracy or in two dimensions. In the constitution example shownin FIG. 1, such a positioning is achieved by employing two positioningrods 25 relative to the glass member 11 and to the opening 21. In analternative constitution, it is possible to use a single positioningelement to be combined with another positioning section.

A measuring apparatus using the above spectrometer according to thisinvention is described below.

FIG. 3 is a perspective view roughly showing the constitution of ameasuring apparatus as an embodiment of this invention. The measuringapparatus of this embodiment is made up of: the spectrometer 1A, a lightsource 55, an optical system 50, a holding member 60, and a measuringcircuit 70. This measuring apparatus is a measuring system that performsanalyses of characteristics and ingredients of a sample S as measuringlight is supplied from the light source 55, is cast onto the sample S,passes through the sample S, and the light component passed through thesample S is measured with the spectrometer 1A. The specific constitutionof the spectrometer 1A is the same as that described above in referenceto FIGS. 1 and 2, and therefore it is omitted in FIG. 3. As for theplacement of the sample S, a sample holder for holding the sample S isplaced, as required, on a support table 61 which will be describedlater.

The optical system 50 is a light guide optical system for guiding light,to be separated with the spectrometer 1A, into the light entry sectionunder predetermined light guide conditions. The optical system 50 ofthis embodiment has a lens 51 for collimating and casting light suppliedfrom the light source 55 onto the sample S and a lens 52 for focusingthe light passing through the sample S onto the spectrometer 1A. Inother words, in the constitution shown in FIG. 3, the lens opticalsystem 50 including the focusing lens 52 is used for optical connectionfor casting the light to be the object of separation onto thespectrometer 1A.

The holding member 60 is provided to hold together the spectrometer 1Aand the optical system 50 that constitute the measuring apparatus. Theholding member 60 has the support table 61 for supporting thespectrometer 1A and the optical system 50, and a connecting plate 62 forconnecting the spectrometer 1A. The connecting plate 62 is erectedupright on the top surface of the support table 61. The light source 55and the optical system 50 are held in place as positioned relative tothe holding member 60 made up of the support table 61 and the connectingplate 62.

The connecting plate 62 is a second connecting member, the other memberdescribed above in relation to the spectrometer 1A, connected to theconnecting flange 20 (See FIG. 1) of the spectrometer 1A. As shown inFIG. 2( a), the connecting plate 62 is also provided with positioningholes 63 to which the positioning rods 25 of the spectrometer 1A arepositioned and inserted.

When the spectrometer 1A of the above constitution is connected to theholding member 60, a simple and highly accurate positioning of thespectrometer 1A and the holding member 60 is achieved through a passivealignment method using the connecting flange (connecting member) 20 ofthe spectrometer 1A and the connecting plate (the second connectingmember) 62 of the holding member 60. In this manner, the light source55, the optical system 50, and the spectrometer 1A are held in the stateof mutually positioned with the holding member 60 made up of the supporttable 61 and the connecting plate 62 with high accuracy.

To describe it more in detail, the spectrometer 1A is positioned in thez-axis direction relative to the light source 55 and to the opticalsystem 50 by the contact between the top surface of the connectingflange 20 (See FIG. 1) of the spectrometer 1A and the surface, on theside of the spectrometer 1A, of the connecting plate 62. Likewise,positioning of the spectrometer 1A is achieved in the x-axis and y-axisdirections as the positioning rods 25 of the spectrometer 1A areinserted into the positioning holes 63 of the connecting plate 62.

The spectrometer 1A is also connected to a measuring circuit 70 throughwirings 71. Thus, detection signals and the like outputted from thephotodiode array 17 are sent to the measuring circuit 70 which carriesout acquisition, processing, and analysis of data as required forspectrometric measurements.

As described above, using the spectrometer 1A having the connectingflange 20 serving as a connecting member and the positioning rods 25serving as positioning elements makes it possible to achieve a measuringapparatus in which the spectrometer 1A is positioned with high accuracyrelative to other component elements of the apparatus through a passivealignment method. Manufacture of the measuring apparatus is facilitatedas the positioning elements are used for positioning the spectrometer1A.

Here, as for setting the light guide conditions of the object light inthe optical system 50, such as setting conditions of focusing of lightto the spectrometer 1A through the lens 52, may be carried out forexample in the constitution shown in FIGS. 2( a) and 3 using thesurface, on the side of the spectrometer 1A, of the connecting plate 62as a reference surface in consideration of characteristic parameters ofthe spectrometer 1A such as the numerical aperture NA (for example inthe order of about 0.2), and the focus depth (apparent focal point). Inthis manner, an optical connection for letting the light to be opticallyseparated enter through the light entry slit 12 into the spectrometer 1Ais achieved under intended conditions.

As for the placement, combination and the like of component elementsother than the spectrometer 1A in the measuring apparatus, they may beappropriately specified according to the type etc. of measurementcarried out with the measuring apparatus. As for the constitution of theholding member for holding the spectrometer and the optical system inthe state of being placed in position, it is not limited to the oneshown in FIG. 3 but may be one including the second connecting memberconnected as another member to the connecting member of thespectrometer. For example, the entire holding member as it is may alsoserve as the second connecting member.

The constitution of the spectrometer according to this invention isfurther described.

FIG. 4 is an exploded perspective view showing the constitution of aspectrometer as a second embodiment of this invention. The spectrometer1B of this embodiment is made up of: the optical body 10, the glassmember 11, and the connecting flange 20. The constitution of the opticalbody 10 and the glass member 11 of this embodiment is similar to that ofthe first embodiment. In FIG. 4, the diffraction grating 16 and thephotodiode array 17 are omitted from illustration.

In relation to the optical body 10, the glass member 11, and others, theconnecting flange 20 is attached to the top surface of a frame member30. The connecting flange 20 is provided with the opening 21 to whichthe glass member 11 is positioned and inserted, and also with the holes22 for securing the connecting flange 20 by means of screws.

In this embodiment, a frame member 30 is placed on the top surface 10 aof the optical body 10 so as to surround the glass member 11. The framemember 30 is provided with two positioning rods 31, one in front of andthe other behind the glass member 11. These positioning rods 31 are of acylindrical shape projecting upward from the optical body 10 and placedin position relative to the glass member 11 and the light entry slit 12.The constitution of the frame member 30, except for the positioning rods31, is shown in a simplified illustration in FIG. 4.

For the above positioning rods 31, the connecting flange 20 is providedwith two insertion holes 26, one in front of and the other behind theopening 21, in positions corresponding to the positioning rods 31, sothat the positioning rods 31 are inserted into the insertion holes 26.In this manner, the positioning rods 31 project upward from theconnecting flange 20 to be positioning members serving as thepositioning elements placed in position relative to the glass member 11including the light entry slit 12.

FIG. 5 is an exploded perspective view showing the constitution of aspectrometer as a third embodiment of this invention. The spectrometer1C of this embodiment is made up of: the optical body 10, the glassmember 11, and the connecting flange 20. The constitution of the opticalbody 10 of this embodiment is similar to that of the first embodiment.The diffraction grating 16 and the photodiode array 17 are not shown inFIG. 5.

The glass member 11 is placed on the top surface 10 a of the opticalbody 10. While the constitution of the glass member 11 is approximatelythe same as that of the first embodiment, two positioning holes 15 areprovided in positions, one in front of and the other behind the lightentry slit 12, as positioned relative to the light entry slit 12.Positioning rods 35 formed in a cylindrical shape and projecting upwardfrom the optical body 10 are secured respectively in the positioningholes 15. In this manner, the positioning rods 35 are placed in positionrelative to the glass member 11 and the light entry slit 12.

In relation to the optical body 10, the glass member 11 and othercomponents, the connecting flange 20 is attached to the top surface 10 aof the optical body 10. The connecting flange 20 is provided with theopening 21 to which the glass member 11 is positioned and inserted, andwith the holes 22 for securing the connecting flange 20 by means ofscrews.

For the above positioning rods 35, the connecting flange 20 is providedwith two insertion holes 27, one in front of and the other behind theopening 21, in positions corresponding to the positioning rods 35, sothat the positioning rods 35 are inserted into the insertion holes 27.In this manner, the positioning rods 35 project upward from theconnecting flange 20 to be positioning elements attached directly andplaced in position relative to the glass member 11 including the lightentry slit 12.

As described above, when the spectrometer 1A using as the positioningelements the positioning rods 25 provided on the connecting flange 20 asshown in FIG. 1 is applied to the measuring apparatus, opticalconnection of the object light to the spectrometer is achieved favorablyby connecting the spectrometer and other members of the measuringapparatus in a simple manner with high accuracy. The same effect isprovided also with the spectrometer 1B shown in FIG. 4 or with thespectrometer 1C shown in FIG. 5, with the former using the positioningrods 31 as positioning elements provided in position relative to thelight entry slit 12, with the latter using the positioning rods 35 aspositioning elements provided in position relative to the glass member11.

The spectrometer and the measuring apparatus according to this inventionare not limited to the above embodiments but may be modified in variousways. For example, as for the constitution of the spectroscopic sectionused for separating the incident object light, various constitutionsother than the above constitution using the optical body 10, thediffraction grating 16, and the photodiode array 17 may be employed.Generally, the spectroscopic section is preferably provided with adispersive element and a photodetector.

As for the specific constitution of the light entry section, while theabove embodiment uses the glass member 11 as the light entry memberformed with the light entry slit 12, the light entry section in adifferent form may also be used. The first positioning section (theopening 21 in FIG. 1) provided on the connecting member and used forpositioning relative to the light entry section may not be provided ifunnecessary.

The specific constitution of the connecting member and the positioningelements are not limited to the above-described connecting flange andthe positioning rods but may be modified in various ways. Generally, anyconstitution of the spectrometer is acceptable as long as it comprises aconnecting member used for connecting the light entry section and thespectroscopic section to the other member and a positioning elementprovided in position relative to the light entry section and used forpositioning the light entry section relative to the other member.

INDUSTRIAL APPLICABILITY

This invention may be used as the spectrometer capable of favorablyachieving optical connection to light to be optically separated and themeasuring apparatus using the spectrometer.

1. A spectrometer comprising: a spectroscopic section used forseparating incident object light into its spectral components, a lightentry section provided in a predetermined position relative to thespectroscopic section for permitting entry of the object light into theinterior of the spectroscopic section; a connecting member used toconnect the light entry section and the spectroscopic section to apredetermined other member; and a positioning element provided aspositioned relative to the light entry section for positioning the lightentry section relative to the other member.
 2. The spectrometer asclaimed in claim 1, further comprising a light entry member in which alight entry slit serving as the light entry section is formed on apredetermined surface.
 3. The spectrometer as claimed in claim 1,wherein the connecting member has a first positioning section used forpositioning relative to the light entry section and a second positioningsection serving as the positioning element.
 4. The spectrometer asclaimed in claim 1, further comprising a light entry member in which alight entry slit serving as the light entry section is formed on apredetermined surface, wherein the connecting member has a firstpositioning section used for positioning relative to the light entrymember and a second positioning section serving as the positioningelement, and wherein the first positioning section includes an openinginto which the light entry member is positioned and inserted.
 5. Thespectrometer as claimed in claim 1, wherein the positioning element ismade of a positioning member positioned relative to the light entrysection.
 6. The spectrometer as claimed in claim 2, wherein thepositioning element is positioned and mounted to the light entry member.7. A measuring apparatus comprising: the spectrometer as claimed inclaim 1; an optical system for guiding the object light to the lightentry section of the spectrometer; and a holding member connected to theconnecting member of the spectrometer for holding the spectrometer andthe optical system as positioned.